下列关于“OTC”的说法正确的是( )
A:非处方药
B:处方药
C:中药
D:西药
It is a good habit of _________ to read a few lines before going to bed.
如图,E为内阻不能忽略的电池,R1、R2、R3为定值电阻,S0、S为开关,V与A分别为电压表与电流表.初始时S0与S均闭合,现将S断开,则( )